KALDI：apply-cmvn-sliding

[wanglong001]

🚀 Feature

Apply sliding-window cepstral mean (and optionally variance)
normalization per utterance.

Motivation

Acoustic features are extracted based on Kaldi. I want to use torchaudio instead, but there is no cmvn， I wrote a torch version of cmvn according to Kaldi

[stonelazy]

Dear @wanglong001 I fail to understand where exactly we would be making use of torchaudio.transforms.SlidingWindowCmn is it to normalize the output of STFT/MFCC at a window level ?
Would it be possible for you to explain on this ? Am not familiar with Kaldi.

[wanglong001]

Dear @wanglong001 I fail to understand where exactly we would be making use of torchaudio.transforms.SlidingWindowCmn is it to normalize the output of STFT/MFCC at a window level ?
Would it be possible for you to explain on this ? Am not familiar with Kaldi.

Yes, normalize the output of cepstral (STFT/MFCC...) at a window level, Mainly to reduce the impact of environmental noise.

https://kaldi-asr.org/doc/apply-cmvn-sliding_8cc.html